This invention relates to probe apparatus for measuring aquatic conditions pertinent to fishing activities and for controlling the condition of the apparatus.
It is known that certain aquatic conditions are favored by fish species and that by locating the existence of said conditions in a body of water a person fishing for such species is more likely to succeed. Aquatic conditions considered pertinent to fishing activities include lighting conditions, such as the amount and spectrum of ambient light, and water characteristics such as temperature, salinity, pH level, velocity, and oxygen content. Measurement of aquatic conditions has been performed utilizing an immersible probe; however, it is not always possible to position the probe near the fishing hook or lure to obtain an accurate picture of the conditions at the hook or lure. It has been proposed, e.g. in U.S. Pat. No. 4,349,976, to combine a fishing lure and a pH sensing probe apparatus in order to locate the lure at the site of measurement. In this system the lure/probe depends from a flexible element which includes a cable for physically supporting the device and a cable for conducting electrical signals generated by the probe. While it is desirable to position the probe adjacent to the fishing lure or hook, it is undesirable to suspend the lure from such a twin cable assembly as such an assembly does not operate with a conventional fishing reel. Depth measuring devices, of the type described in Time magazine, June 6, 1988, page 62, have been used to measure the distance from the water surface to the bottom of a body of water or to a school of fish, but no device is known which indicates the depth of a fishing hook or lure. While it is possible to measure the amount of fishing line extending from a fishing reel, this measurement does not accurately reflect the depth of the hook, as the line does not always hang vertically in the water.